Fastening device for airplane cowls and the like



Sept. 26, 14939. 2,174,030

FASTENING DEVVICE FOR AIRPLANE cowLs AND THE LIKE Filed Sept.. l, 1938 INVENTOR R n oww ffm N.T M.M M W mm E Q gw; @u

Patented Sept. 26, 1.939

UNITED STA-TES FASTENING DEVICE FOR AIRPLANE COWLS AND THE LIKE wammi'r. Boyer, Stamford, conn.

Application September 1,v 1938, Serial No. 227,946

5 Claims.

The invention relates to fastening devices particularly adapted to hold together metal panel members such as are used for example in air- -plane cowls. Particularly for the latter use there 5 are several stringent requirements due to the stresses to which the devices are subject when in use. There is a considerablemechanical vibration due to the engine and propeller and also a vibration due to the high velocity of the air l past thev cowl surfaces which the devices must be capable of withstanding. The fastening de vices must present a. flush outer surface. They must be rapidly and easily tightened or loosened without leaving disconnected parts which might l become lost.

The manner in which the fastening device of the present invention accomplishes these results will be more easily understood with referenceto the accompanying drawing, in which- Fig. 1 is an inside -view of the fastener;

Fig. 2 is a side elevation "thereof, partly broken away; and Y Fig. 3 is a section on line 3-3 of Fig. 1.

The fastener comprises a fixed member III preferably of corrosion resisting spring material having a substantially flat central portion and end portions connected therewith by arcuate segments II, and secured as by rivets I2 or welding to the metal covering of the airplane to which the cowling, hand-hole cover, or other part I4 is to be secured. The'body member I0 is preferably apertured as at I5 to permit access to the head of the rivet and 'to increase the IeXIbiIity. The cowl piece II! may have a lining I6 and the two laminations are bent inwardly as at I1 adjacent each hole I8 where a fastener is to be secured.

Through each of these holes is passed a bolt I9` having a cannelure 20 into which a grommet 2| isformed so as'to embrace the parts I4 and I6.

The external face 22 of the bolt I9 is made flush with the adjacent face of the member Il, and is formed with a screwdriver slot 23 or other suitable means by which the bolt may be rotated.

,Extending crosswise through a slot 24 in the 46 inner end of the bolt is a bar 25 formed with a projecting portion 26 preferably positioned intermediate the length ofthe bolt. The bar 25 is held in place as by a pin or rivet 21. The end of 4the bolt I9 and the corresponding portion'of the bar 26 are beveled as at 28 to facilitate its entry into thelocking apparatus. It will be understood that once the grommet 2| is formed in place, the bolt I9 is an integral although a rotatable part of the composite member I4I6. I!

the bolt is in unlocked position it and themem-- ber I4-I6 can be removed as a unit without the danger of the bolt becomingdisplaoed.

The locking mechanism Will now be described. It comprises besides .the extensions 26 previously referred to, pairs of oppositely directed wings 5 struck up from the material of the body mem er I0. One pair 30 of these wings extends downwardly while the other pair 3| extends upwardly as best shown in Fig. 3. An inclined space 32 is formed between each pair of the members 30, 3l l0 of suiiicient height to permit the passage of the extending portion 26 of the cross bar. The upstanding wings 3I might be omitted if desired,

but 'they add somewhat to the strength of the device. tated to the right the projections 26 will pass vthrough this slot, the cross piece riding upwardly on the inclined surface of the wings 30. If this rotation is continued sufliciently the extensions 26 will ride into depressions 33 formed in the k20 otherwise flat top of the body member III. The sides f the extensions 26 contacting with the body member are preferably rounded as shown so movement ofthe fixed member I0 adjacent the zones of coupling at the' rivets I2 or a spring mounting for the bolt I9. It will be observed that the body member I0 is secured rigidly to the 35 l plate I3 and that the construction does not require .iiexibility adjacent this point, so that undesired bending which would tend to work the rivets loose is avoided. The central portion Bof the xed member, however, is at and furthermore is broken up both by the holes I5 and the slot 32. The whole inner side of the body member is therefore flexible; the bends II needing to yield only enough to accommodate the very slight change in'overall length .as the body mem- 45 together, arcuate segments connecting said cen- 55' If the bolt is pushed inwardly and 'rol5 Ails tral portion with said end portions, said central portion having a centrally positioned aperture and having slots extending from vsaid aperture, the nxed member having portionsv adjacent the slots bent towards the end portions to form inclined guides, said fixed member having depressions extending laterally of the central aperture intermediate the slots, a bolt secured for rotative movement but against longitudinal movement to the second of the members to be fastened together, a cross piece secured to said bolt and extend-I ing laterally thereof into position to pass through said slots and to be received in said depressions, the exposed end of the bolt having means whereby it may be rotated.

2. A fastener for airplane cowls and the like which comprises a fixed member having a cen' trally substantially fiat portion and end portions spaced therefrom and in substantial parallelism therewith for rigid connection to one of the members to be fastened together, arcuate segments connecting said central portion with said end portions, said central portion having a centrally positioned aperture and having 'slots extending from said aperture, the xed member having those portions adiacent the slots bent alternately toward and away from the end portions to form opposed inclined guideways between them, said fixed member having depressions extending laterally of the central aperture intermediate the slots, a bolt secured for rotative movement but against longitudinal movement to the second of the members to be fastened together, and a cross piece secured to said bolt and extending laterally thereof into position to pass through said slots and to be received in vlsaid depressions. the exposed end of the bolt having means whereby it may berotatedr 3. A fastener for airplane cowls and the like which'comprises a xed member having a central ysubstantially fiat portion and end portions spaced therefrom and in substantial parallelism therewith for rigid connection to one of the members to be fastened together, arcuate Segments connecting said central portion with saidl end portions, said fixed member having apertures to permit access to the end portions at the point of such lrigid connection and to increase the flexibility of the member, saidcentral portion having a centrally positioned aperturel and having slotsvextending longitudinally therefrom into said ilrst named apertures, the fixed member having portions adjacent the slots bent Ctowards the end portions to form inclinedguides, said fixed member havingdepressions extending laterally of the central aperture intermediate the slots, a bolt se- `cured for rotative movement but against longitudinal movement to the second of the members to be fastened together, and a cross piece secured to said bolt and extending laterally thereof into position to pass through said slots and to be received in said depressions, the exposed end of the bolt having means whereby it may be rotated.

4. A fastener for airplane cowls which comprises a fixed member having a central substantially flat portion and end portions spaced therefrom and in substantial parallelism therewith for rigid connection to one of the members to be fastened together, arcuate segments connecting said central portion with said end portions, said central portion having a centrally positioned aperture and having slotsextending from said aperture, the nxed member having portions adjacent the slots bent towards the end portions to form position to pass through said slots and to be received in said depressions, the end of the bolt remote from the cross piece having a screwdriver slot positioned in line with the direction of air flow.-

5. A fastener for airplane cowls and the like which comprises a fixed member having a central substantially iat portion and end portions spaced therefrom and in substantial parallelism therewith for rigid connection to one of the'members to be fastened together, arcuate segments connecting said-central portion with said end porhaving extensions extending laterally of the boltl in'to position to pam through said slots and to be received in said depressions, the exposed end of vthe bolt having means wherebyit -may be rotated. l

' WALTON T. BOYER. 

